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Effect of adhesive cure on quality of fingerjoined lumber

https://library.fpinnovations.ca/fr/permalink/fpipub39328
Auteur
Pirvu, Ciprian
Date
March 2011
Genre du document
Research report
Domaine
Wood Manufacturing & Digitalization
Auteur
Pirvu, Ciprian
Collaborateur
Natural Resources Canada. Canadian Forest Service.
Date
March 2011
Genre du document
Research report
Description physique
45 p.
Secteur
Wood Products
Domaine
Wood Manufacturing & Digitalization
Champ de recherche
Advanced Wood Manufacturing
Sujet
Joints
Série
Value to Wood No. FPI 121W
W-2809
Localisation
Vancouver, British Columbia
Langue
English
Résumé
The relationship between proof load level of fingerjoined lumber and degree of cure of adhesive bonds was investigated. Tension tests were completed for two different degrees of cure for a single adhesive. The proof load level determined for the partially cured joints did not cause damage to the joints that survived the proof test. Preliminary guidelines for determining appropriate proof load levels for testing fingerjoined lumber with partially cured joints were proposed. The proposed guidelines will need to be validated through mill trials to demonstrate their efficacy and reliability to the manufacturer and third party inspection agency.
Fingerjoined lumber
Glued joints - Finger
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Effect of adhesive cure on quality of fingerjoined lumber : updated report

https://library.fpinnovations.ca/fr/permalink/fpipub39405
Auteur
Pirvu, Ciprian
Date
March 2012
Genre du document
Research report
Domaine
Wood Manufacturing & Digitalization
Auteur
Pirvu, Ciprian
Collaborateur
Natural Resources Canada. Canadian Forest Service.
Date
March 2012
Genre du document
Research report
Description physique
56 p.
Secteur
Wood Products
Domaine
Wood Manufacturing & Digitalization
Champ de recherche
Advanced Wood Manufacturing
Sujet
Lumber
Composites
Adhesives
Série
Value to Wood No. FPI 121W
W-2888
Localisation
Vancouver, British Columbia
Langue
English
Résumé
The relationship between proof load level of fingerjoined lumber and degree of cure of adhesive bonds was investigated. Tension tests were completed for two different degrees of cure for two different adhesives. The proof load level determined for the partially cured joints did not cause damage to the joints that survived the proof test. Preliminary guidelines for determining appropriate proof load levels for testing fingerjoined lumber with partially cured joints were proposed. The proposed guidelines will need to be validated through mill trials to demonstrate their efficacy and reliability to the manufacturer and third party inspection agency. Keywords: fingerjoined lumber; tension proof testing/loading; partially cured adhesive bonds.
Curing rate
Finger jointed lumber
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In-situ testing of wood innovation and design centre: floor vibration, building vibration, and sound insulation performance

https://library.fpinnovations.ca/fr/permalink/fpipub53039
Auteur
Hu, Lin J.
Pirvu, Ciprian
Ramzi, Redouane
Date
July 2015
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Hu, Lin J.
Pirvu, Ciprian
Ramzi, Redouane
Collaborateur
Forestry Innovation Investment
Date
July 2015
Genre du document
Research report
Description physique
49 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Advanced Wood Materials
Sujet
Testing
Performance
Wood
Buildings
Langue
English
Résumé
This report describes the building, tested floor and wall assemblies, test methods, and summarizes the test results. The preliminary performance data provides critical feedback on the design of the building for resisting wind-induced vibration and on the floor vibration controlled design. The data can be further used to validate the calculation methods and tools/models of dynamic analysis. Originally confidential to FII, they have provided permission to make the report available.
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Refinement of duration of load test protocols

https://library.fpinnovations.ca/fr/permalink/fpipub39406
Auteur
Pirvu, Ciprian
Date
March 2012
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Pirvu, Ciprian
Collaborateur
Natural Resources Canada. Canadian Forest Service.
Date
March 2012
Genre du document
Research report
Description physique
40 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Building Systems
Sujet
Strength load bearing
Mechanical properties
Specifications
Loads
Specification
Série
Canadian Forest Service No. FRII-3.17
W-2892
Localisation
Vancouver, British Columbia
Langue
English
Résumé
Duration of load (DOL) and creep effects characterize rheological behaviour of wood and are of critical importance to timber engineering. These effects are accounted for in the engineering design codes with adjustment factors for structural wood and wood-based products. Various methods are used worldwide for the evaluation of DOL and creep effects and for determination of appropriate adjustment factors. A review of the major international codes for engineering design in wood was carried out to understand how DOL and creep are taken into account in these codes and provide recommendations on how to level out the main differences between the codes. It is recommended to adopt an internationally recognized method for evaluation of DOL and creep, and suggestions for the contents of such a method are provided. Statisticians were engaged to evaluate the damage accumulation models used in wood industry for assessing DOL and creep effects of wood products. The research undertaken yielded answers to whether the mathematical models can be improved, if times-to-failure for ramp and constant load tests can be approximated by Weibull or log-normal distributions, and whether some model parameters can be assumed constant and other treated as random effects. An experimental study was carried out to support the statistical work. The results of the study were used in statistical simulations to estimate the parameters used in the damage accumulation models in an attempt to refine the current models.
Strength - Load bearing - Influence of duration
Strength - Load bearing - Specifications
Strength - Load bearing - Tests
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Time-dependent behavior of cross-laminated timber

https://library.fpinnovations.ca/fr/permalink/fpipub43013
Auteur
Pirvu, Ciprian
Date
March 2014
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Pirvu, Ciprian
Collaborateur
Natural Resources Canada. Canadian Forest Service.
Date
March 2014
Genre du document
Research report
Description physique
70 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Advanced Wood Materials
Sujet
Building construction
Design
Laminate product
Panels
Timber
Série
Transformative Technologies No. 1.1.12
W-3092
Langue
English
Résumé
Cross laminated timber (CLT) panels were manufactured and tested to assess their time dependent behaviour. This study is intended to help guide the development of an appropriate test method and acceptance criteria to account for duration of load and creep effects in the design of structures using CLT. Nine CLT panels of different qualities and using different wood species combinations were manufactured at a pre-commercial pilot plant out of local wood species. The CLT panels manufactured in this study were pressed at about 54% lower pressure than the minimum vertical pressure specified by the adhesive manufacturer due to a limitation of the press, so the CLT panels are viewed as a simulated defective sample, which may occur in a production environment due to material- or process-related issues. Full-size CLT panels were initially tested non-destructively to assess their bending stiffness. Then, billets were ripped from the full-size CLT panels, and tested to failure in 1-minute and 10-hour ramp tests, or assessed in creep tests under sustained load. The constant loads imposed on the CLT billets tested in creep were calculated as to allow for a maximum deflection of L/180. Following two cycles of loading and relaxation, the CLT billets tested in creep were further tested to failure at the end. The principles of ASTM D6815-09 and those of an in-house FPInnovations protocol were applied to assess the time dependent behavior of the CLT billets. The main test findings are summarized below:
In terms of residual stiffness, the percentage change in the initial bending stiffness for the CLT billets subjected to the 10-hour ramp test varied between 0-5%, showing a 3% drop in stiffness on average, while that for the CLT billets tested in creep ranged between 0-3%, showing a 1% stiffness drop on average. These are regarded as relatively small changes in bending stiffness.
In general, decreasing creep rates were observed on most of the CLT billets especially in the first cycle up to 90 days. The creep rates went up after 120 days of loading due to an increase in temperature and relative humidity conditions, which greatly affect the rate of deflection and recovery of wood products.
Fractional deflections were calculated for all the CLT billets after 30-day intervals and found to be less than or equal to 1.43.
Creep recovery was above 36% after 30-day, 60-day, and 90-day recovery periods in the first cycle. However, in the second cycle, creep recovery for some CLT billets dropped below 20% for certain time periods. ASTM D6815-09 provides specifications for evaluation of duration of load and creep effects of wood and wood-based products. The standard was designed to accommodate wood products that can be easily sampled, handled, and tested under load for minimum 90 days and up to 120 days. The standard requires a minimum sample size of 28 specimens. Because of its large dimensions, CLT products are not feasible for experiments requiring such large sample sizes. However, the findings of this study revealed potential for some of the acceptance criteria in ASTM D6815-09 to be applied to CLT products. The CLT billets in this study were assessed in accordance to the creep rate, fractional deflection, and creep recovery criteria in ASTM D6815-09 standard. All CLT billets tested in this study showed (1) decreasing creep rates after 90/120 days of loading, (2) fractional deflections less than 2.0 after 90-day loading, and (3) higher creep recovery than 20% after 30 days of unloading, as required by ASTM D6815-09. A single replicate billet was used per CLT configuration instead of the minimum sample size required by the standard which may have an effect on the findings.
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